Objective:To explore the effects of high-intensity interval training(HIIT)and semaglutide on cardiomyopathy and glycophagy in db/db mice.Method:Forty male db/db mice were randomly divided into diabetic control group(DC,n=10),diabetic+exercise group(DE,n=10),diabetic+semaglutide group(DM,n=10)and diabetic+exercise+semaglutide group(EM,n=10).DE mice and EM mice were conducted a 8-week HIIT treadmill protocol,DM mice and EM mice received daily subcutaneous neck injections of semaglutide at 0.05mg/kg.Body weight and fasting blood glucose were measured regularly.Echocardiography was used to detect cardiac function at the end of the intervention.Myocardial morphology was evaluated by H&E staining;The H&E staining was used to observe the myocardial morphological changes;fibrosis by Masson staining;glycogen accumulation by periodic acid-Schiff staining;and cardiomyocyte hypertrophy by wheat germ agglutinin(WGA)staining.The glycophagy was observed by transmission electron microscopy.Western Blot quantified the IRS-1,P-PI3K,PI3K,p-AKT,AKT,p-GSK3β,GSK3β,p-AMPK,AMPK,p-mTOR,mTOR,LC3Ⅱ/Ⅰ,TFEB and GABARAPL1 in myocar-dial tissue.Result:Compared with DC group,HIIT and/or semaglutide intervention reduced body weight and fasting glu-cose,improved cardiac function and myocardial morphology,decreased fibrosis and cardiomyocyte hypertrophy(reduced cross-sectional area,P<0.05),and lowered glycogen accumulation.Autophagosomes and autophagy vac-uoles containing different amounts of glycogen granule were observed by transmission electron microscopy.Compared with DC group,the protein level of p-mTOR/mTOR in DE mice was significantly decreased,and the protein levels of LC3Ⅱ/Ⅰ,TFEB and GABARAPL1 in DE mice were significantly increased(P<0.05).The phosphorylation levels of AKT and GSK3β in DM mice was significantly increased,and the protein level of TFEB and GABARAPL1 in DM mice was significantly increased(P<0.05).The protein levels of IRS-1,LC3Ⅱ/Ⅰ,TFEB and GABAPARAL1 in EM mice significantly increased,the phosphorylation levels of PI3K,AKT,GSK3β and AMPK were significantly increased.The p-mTOR/mTOR ratio of autophagy negative regula-tor in EM mice was decreased(P<0.05).Compared with single treatment group,the AMPK phosphorylation and LC3Ⅱ/Ⅰ protein expression in EM group were significantly increased(P<0.05).Conclusion:HIIT and semaglutide can improve myocardial fibrosis,glycogen accumulation and cardiac func-tion in db/db mice,and the combined intervention group yields the most pronounced effects,which may be re-lated to AMPK/mTOR pathway activation,enhanced cardiac glycophagy,and reduced myocardial injury.

Objective:To explore the effects of high-intensity interval training(HIIT)and semaglutide on cardiomyopathy and glycophagy in db/db mice.Method:Forty male db/db mice were randomly divided into diabetic control group(DC,n=10),diabetic+exercise group(DE,n=10),diabetic+semaglutide group(DM,n=10)and diabetic+exercise+semaglutide group(EM,n=10).DE mice and EM mice were conducted a 8-week HIIT treadmill protocol,DM mice and EM mice received daily subcutaneous neck injections of semaglutide at 0.05mg/kg.Body weight and fasting blood glucose were measured regularly.Echocardiography was used to detect cardiac function at the end of the intervention.Myocardial morphology was evaluated by H&E staining;The H&E staining was used to observe the myocardial morphological changes;fibrosis by Masson staining;glycogen accumulation by periodic acid-Schiff staining;and cardiomyocyte hypertrophy by wheat germ agglutinin(WGA)staining.The glycophagy was observed by transmission electron microscopy.Western Blot quantified the IRS-1,P-PI3K,PI3K,p-AKT,AKT,p-GSK3β,GSK3β,p-AMPK,AMPK,p-mTOR,mTOR,LC3Ⅱ/Ⅰ,TFEB and GABARAPL1 in myocar-dial tissue.Result:Compared with DC group,HIIT and/or semaglutide intervention reduced body weight and fasting glu-cose,improved cardiac function and myocardial morphology,decreased fibrosis and cardiomyocyte hypertrophy(reduced cross-sectional area,P<0.05),and lowered glycogen accumulation.Autophagosomes and autophagy vac-uoles containing different amounts of glycogen granule were observed by transmission electron microscopy.Compared with DC group,the protein level of p-mTOR/mTOR in DE mice was significantly decreased,and the protein levels of LC3Ⅱ/Ⅰ,TFEB and GABARAPL1 in DE mice were significantly increased(P<0.05).The phosphorylation levels of AKT and GSK3β in DM mice was significantly increased,and the protein level of TFEB and GABARAPL1 in DM mice was significantly increased(P<0.05).The protein levels of IRS-1,LC3Ⅱ/Ⅰ,TFEB and GABAPARAL1 in EM mice significantly increased,the phosphorylation levels of PI3K,AKT,GSK3β and AMPK were significantly increased.The p-mTOR/mTOR ratio of autophagy negative regula-tor in EM mice was decreased(P<0.05).Compared with single treatment group,the AMPK phosphorylation and LC3Ⅱ/Ⅰ protein expression in EM group were significantly increased(P<0.05).Conclusion:HIIT and semaglutide can improve myocardial fibrosis,glycogen accumulation and cardiac func-tion in db/db mice,and the combined intervention group yields the most pronounced effects,which may be re-lated to AMPK/mTOR pathway activation,enhanced cardiac glycophagy,and reduced myocardial injury.

Objective To investigate the role of TLR4/NF-κB signal pathway in pathogenesis of brain inju-ry during deep hypothermia circulatory arrest(DHCA). Methods BV2 microglia cells were subjected to oxygen-glucose deprivation/reoxygenation(OGD/R),in vitro model for DHCA. The BV2 were randomly divided into the control group(C group)and the experimental group(O group). BV2 viability was determined by CCK-8 assay. TLR4 and its downstream signaling molecules ,MyD88 and phosphorylated NF-κB (p-p65) expressions were detected by Western blotting. TLR4 mRNA expression in BV2 microglial cells were determined by RT-PCR. Level of interleukin-6 (IL-6) and tumor necrosis factor alpha (TNF-α) in culture medium was detected by ELASA. Results Compared with the group C,BV2 microglia cell viability in experiment group was obviously weaker(P<0.05). Expressions of TLR4,MyD88 and phosphorylated NF-κB(p-p65)from the experiment group increased remarkedly than those from the group C (P < 0.05). TLR4 mRNA level was higher significantly in the group O than in the group C (P < 0.01). Production of IL-6 and TNF-α in the group O were up-regulated apparently compared to the group C(P<0.01). Conclusion TLR4/NF-κB signaling pathway contributed to activation of BV2 microglia cells treated by OGD/Reoxygenation ,which was probably the exactly way that involved in pathogenesis of brain injury during deep hypothermia circulatory arrest.

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